Intercepting-valve for compound engines.



H. R. STAFFORD. INTERCEPTING VALVE FOR COMPOUND ENGINES.

APPLICATION FILED OCT. 2. 1915.

Patented Mar. 14, 1916.

2 SHEETSISHEET 1 Gain/7901,6225). 2%?) WITNESSES FWM T coLuMulAPLANOGRAPH co., WASHINGTON D c H. R. STAFFORD.

INTERCEPTING VALVE FOR COMPOUND ENGINES.

APPLICATION FILED OCT. 2, I9I5.

1,175,087. Patented Mar. 14, 1916.

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NVENTOR fidayym, flaw i p TliTES PATENT EFTC,

HAL R. STAFFORD, OF PLAINFIELD, NEW JERSEY.

INTERGEPTING-VALVE FOR COMPOUND ENGINES.

Application filed October 2, 1915.

To all whom it may concern:

Be it known that I, HAL R. STAFFORD, of Plainfield, in the county ofUnion and State of New Jersey, have invented a certain new and usefulImprovement in Tntercepting- Valves for Compound Engines, of whichimprovement the following is a specification.

My present invention is an improvement upon that for which LettersPatent of the United States No. 1,066,232 were granted and issued to meunder date of July 1, 1913, and its object is to enable the advantagesthereof to be attained with a simplification of mechanism andcorresponding economization of structural and maintenance cost.

The improvement claimed is hereinafter fully set forth.

In the accompanying drawings: Figure 1 is a longitudinal centralsectionthrough an intercepting valve mechanism embodying my invention,the parts being shown in position when working as a compound engine,and; Fig. 2, a similar section, the parts being shown in position whenworking as a simple or single expansion engine.

Referring to the drawings, the intercepting valve mechanism is, as inLetters Patent No. 1,066,232 aforesaid, fitted in a casing, 16, ofsubstantially cylindrical form, which is separate from the highpressure'cylinders of the engine, and adapted to be connected detachablythereto and supported in any suitable and convenient manner. The interior of the casing is divided, by transverse partitions, 16*, 16, and16 into a high pressure exhaust chamber, 17; an independent or directexhaust chamber, 18; a receiver chamber, 19; and a live steam chamber,20. Two curved passages, 17 lead from the high pressure exhaust chamber,17, to openings in the wall of the casing, 16, which, when the casing issecured in position on the high pressure cylinders, register with theopenings of the exhaust passages of said cylinders, ball joint ringsbeing interposed at the joints to insure tightness while permitting alimited degree of' relative movement. Instead of controllingcommunication between the high pressure exhaust chamber and the receiverby an intercepting valve, and betweenthe high pressure exhaust chamberandthe direct exhaust chamber by a separate and independent direct oremergency exhaust valve, as has ordinarily been the practice prior tothe invention of Patent No. 1,066,- 232 aforesaid, I provide, as in saidpatent, a

Specification of Letters Patent.

Patented Mar. 14:, 1916.

Serial No. 53,693.

single valve, 21, which, operating in combination with a reducing valve,performs the functions of the two independent valves of the prior art,and which I therefore term an intercepting and direct exhaust valve. Thevalve, 21, is fixed upon a stem, 22, by the movements of which, aspresently to be described, it is either closed on a seat, 16 surroundingan opening in the partition, 16, when the locomotive is working as acompound engine, as shown in Fig. 1, or on a seat surrounding an openingin the partition, 16, when the locomotive is working as a simple engine,as shown in Fig. 2. The seat, 16 ,'is made integral, and in lineaxially, with the operating cylinder, 24, here- .inafter specified, andis connected therewith by radial ribs or webs, 2%.

The stem, 22, of the intercepting and direct exhaust valve carries, uponone of its ends, a properly packed piston, 23, which is fitted tomovelongitudinally in a combined operating and dash pot cylinder, 24,connected detachably to one of the ends of the casing, 16, in whichthere is formed an opening through which said cylinder, together withthe valve, 21, and its stem, may be inserted and removed, as desired.The stem, 22, passes, with a comparatively loose fit, through an openingin the inner head of the cylinder, and the outer end of the cylinder isclosed by a detachable head, 24, in which trolling the supply of steamfrom the boiler to the cylinder through the pipe, 25. The simpling valvemechanism is fully described and'shown in Patent No. 1,066,232, and asit does not, in and of itself, form part of my present invention, it isnot herein described.

The stem, 22, is reduced in diameter for a portion of its length, on theside of the valve, 21, farther from the cylinder, 24, and a reducingvalve dash pot piston, 27, is formed or fixed upon it, at the end of itsreduced portion, said piston fitting, and working longitudinally, in areducing valve dash pct, 28, formed'in a tubular reducing valve, 28,said valve having a piston, 28*, adjoining its end in which the dash potis formed, a piston, 28, of smaller diameter, at its opposite end, andan intermediate piston, 28

The mechanism, so far as hereinbefore de scribed, accords, except as tothe reducing valve, with that of Letters Patent No. 1,066,232,aforesaid, and the further improvement of my present invention will nowbe described. The reducing valve pistons, instead of working in a mainsteam admission valve, as in said patent, are, in my improvedconstruction, fitted' directly in a sleeve or bushing, 30, which isfixed in the partition, 16 of the'casing, and in a cylinder, 31,projecting therefrom. andclosed, at'

its outer end, by a removable head, 31, said bushing extending throughthe live steam chamber, 20, and the receiver chamber, 19. Live steamfrom the-chamber, 20, is continuously admitted to the interior of thebushing, 30, through ports, '30, therein. The main live steam admissionvalve, 29, of Patent No. 1,066,232, is, under my present inventiondispensed with, and its function, i. 6., that of cutting off the flow oflive steam to the receiver chamber when workingcompound, is performed bythe intermediate piston, 28 of'the reducing valve, which, by

ponclerance of pressure acting toward the larger piston, 28. 7

It will be seen that by the modification of structure of the reducingvalve above de, scribed, it is enabled to perform two functionsadditional to its original one, and the main livesteam admission valveis thereby dispensed with, correspondingly effecting a substantialsimplification of the mechanism and a reduction of the cost ofmanufacture, and rendering the entire appliance more positive in itsaction and more easily main tained in operative condition.

The smaller piston, 28, of the reducing valve, is constantly subject toatmospheric pressure on its outer side, through the chamber of thecylinder, 31, which is closed by the head, 31, and through a pipe, 31*,leading therefrom to a separate exhaust pipe, 32, which discharges intothe smoke box of the locomotive.

In operation, when it is desired to work the locomotive as asimpleengme, steam from the boiler is admitted by the engineer to theoperating and dash pot cylinder, 24, .bythe manipulation of theoperating or simpling valve mechanism. The intercepting and directexhaust valve, 21, isthereby moved by the pressure on the outer side ofthe piston, 23, to, its seat in the partition,

16, closing communication between the high pressure exhaust chamber andthe receiver chamber, and' opening communication be tween the highpressure exhaust chamber and the'direct exhaust chamber and 'sepa rateexhaust pipe, The valve is seated without shock by reason of thecompression of the fluid contents of the dash; pot formed by the spaceon the inner sideof the piston, 23. In this traverse, the reducingvalve, 28, is moved by:thepressure of the piston, 27, on the bottom ofthe dash pct, 28, into position in which the piston, 28 opens the ports,

.30, thereby allowing boiler steam, at a reduced pressure (determined bythe relative diameters of the pistons, 28 and 28) to flow from the livesteam chamber, 20, through the space in the bushing, '30, surroundingthe reducing valve, and the ports, 30, into; the

receiver chamber, 19, and thence directly to the lower pressurecyhnders.The exhaust from the high pressure cylinders is disharged directlythrough the sepamfe haust pipe, 32. r Y r V When it is desired to workas-a compound engine, the engineer releases .thepressure from theoperating cylinder, 24:, by proper movement of the simpling valvemechanism,

whereupon the pressure of the live steam on the differential pistons, 28and 28, of the reduc ng valve, moves the valve, 21, to its seat in thepartition, 16, and brings the reducing valve into the position shown inFig. 1. The exhauststeam from; the high pressure cylinders is thendischarged into 7 the receiver chamber, and thence to the low pressurecylinders, and the direct supply of live steam to'the low pressurecylinders iscutoff. r

Among the entinvention attains, in addition to those'of the constructionset forth in Patent No. 1,066,232 aforesaid, there-arespecially to benoted those of a material reduction in the number of packing rings ascompared with prior lnterceptmg valve mechanisms, and

reduction in the number of working parts.

advantages .which my pres the performance of a number of functions by asmgle unit, thereby effecting a material I claim as my invention anddesire to se-,

cure by Letters Patent a 1. In a compound engine, the'c ombination of aninterceptingvalve casing'hav-ing, a separate exhaust chamber, a receivercham her, and an interposed high pressure exhaust chamber,-op'eningsbeing formed in the partitions between said chambers; an

operating cylinder fixed to the casing; a piston working therein; a stemfixed to said piston; a single valve fixed to said stem and adapted tocontrol each of the partition openings, a reducing valve movable by'and1n lme With said stem, and having a limited Cir steam admission throughthe ports,

degree of traverse independent thereof; a fixed bushing in which saidreducing valve is fitted to operate and which communicates with a sourceof live steam supply; ports leading from the interior of the bushing tothe receiver chamber; an end piston head, 28*, carried by the reducingvalve and controlling communication between the inte rior of the bushingthereof and the receiver chamber, when the engine is working simple anopposite end piston head, 28 of smaller diameter closing communicationbetween the interior of the bushing and the atmos phere; and anintermediate piston head, 28 also carried by said valve and cutting ofileading from the interior of the bushing to the receiver chamber, whenthe engine is working compound.

2. In a compound engine, the combination of an intercepting valve casinghaving a separate exhaust chamber, a receiver chamber, and an interposedhigh pressure exhaust chamber, openings being formed in the partitionsbetween said chambers; an operating cylinder fixed to the casing; apiston working therein; a stem fixed to said piston; a single valvefixed to said stem and adapted to control each of the partitionopenings; a reducing valve movable in line with said stem; a fixedbushing having bores of different diameters in which said reducing valveis fitted to operate and which communicates with a source of live steamsup ply; ports leading from the larger bore of the bushing to thereceiver chamber; end

Copies of this patent pistons on the reducing valve fitting thedifferential bores of the bushing; and an intermediatepiston on saidvalve which cuts off steam admission through the receiver ports of thebushing.

3. In a compound engine, the combination of an intercepting valve casinghaving a separate exhaust chamber, a receiver chamber, an interposedhigh pressure exhaust chamber, and a live steam supply connection,openings being formed in the partitions between the chambers; anoperating cylinder fixed in the casing; a piston worle ing therein; astem fixed to said piston; a single valve fixed to said stem and adaptedto control the partition openings; and a differential piston valvemember which is controlled by said stem, and which is provided with anintermediate piston which cuts off the admission of steam at reducedpressure from the live steam supply connection to the receiver chamber.

4. In a compound engine, the combination of an intercepting valvecasing, an intercepting valve controlling steam passages therein, and areducing valve operating in connection with said intercepting valve andcomprising a tubular body, two end pistons or differential diameters,and a perforated intermediate piston corresponding in diameter with thelarger end piston.

HAL R. STAFFORD.

Witnesses:

HELEN F. MoDEvrrT, JAs. MCLAUGHLIN.

Commissioner of Patents,

Washington, D. 0.

